There seems to be a bug with code folding and group tabbing. Let say I have a loop that is code folded. I highlight the first line of this loop (e.g. "for i in ... ) and tab it. One would expect such tabbing to indent the entire code block. However, somehow, after such tabbing, the code folding sign [+] on the left margin disappears and I am left with only one line of the code -- the first line of the loop. (It turns out that the rest of the code is still there, but the left margin does not show the folded state.)